This invention relates to card counters and, more particularly, to a card counter card loading assembly which is self-adjustable for optimum sensing of stacks of cards of varying height.
The credit card counter 10 of the copending application Ser. No. 246,516, filed Sept. 19, 1988, for "Credit Card Counter and Method of Using Same" of the present inventor and assignee of this application, shown in FIGS. 1A and 1B, and of prior known units, are provided with a fixed card shelf 12 upon which a stack 14 of substantially identical cards 14A, such as plastic credit cards, is supported usually within a box 16 with the top edges 18 in vertical alignment beneath a sensor assembly 19 including an optical sensor 20, FIG. 1B, within a counter housing 22. The sensor 20 is focused through a cylindrical lens 24 at a focal point, or sensing location 26, which is a preselected distance beneath the sensor 20. Light from a source 28 passes through the lens 24, and is reflected off the edges 18 of the cards 14A in succession as the sensor 20 moves along a scan track extending across the back of the card shelf 12 in the direction of arrows 30 substantially transverse to the edges 18 of the cards and parallel to the front edge of the card shelf 12. The sensor 20 generates an electrical pulse for each light fluctuation which it "sees" whenever it passes the top edge 18 of a card 14A. These pulses are then electronically counted, stored, compared, displayed and otherwise used to maintain card inventory records. Reference should be made to the aforementioned U.S. patent application for further details.
This counter 10 works completely satisfactorily so long as the stack of cards 14 is at a precise standard height with the top edges 18 of the cards being precisely located at the sensing location and in focus by the optical sensor 20 for optimum sensing. However, when stacks of cards 14, usually in boxes 16, vary in height 32 such that the top edges 18 of the cards 14A are not located at the fixed focal point, the sensor does not "see" so well. As a result of blurred images of card edges 18, there are correspondingly indistinct electrical signals generated by the sensor instead of the strong pulses required for reliable detection. Accordingly, detection errors and thus counting errors can occur in those instances.
As cards, such as credit cards, debit cards, identification cards, key cards and the like have proliferated and become virtually ubiquitous in western society, the precise height standards to which they once conformed no longer prevail. This is due in part to variations in the boxes 16 in which they are usually stored and shipped as well as variations in the cards 14A themselves, such that it has become necessary to provide some means for adjustment for stacks of cards 14 of different heights. While the cards 14A are usually in boxes, this is not necessarily the case when counting cards. The phrase rack of cards 14 herein shall be used to mean the combination of the cards 14A and the box 16 in which they are contained, if in a box, and if not in a box, it shall be intended to mean the stack of cards, alone.
One known card counter employs a card loading system in which gravity is employed in part to insure that the edges of the cards are properly located at the sensor location 26; the box of cards is turned upside down, or upended, and partly lain directly on top of an alignment member which holds them in the correct position for optimum sensing. After counting the box of cards, the box is then turned right side up to a nonupended orientation, removed from the loading mechanism and replaced with another box. Some boxes are filled and covered with shrink wrap plastic or the like which prevents them from falling out of the box when turned over; however, other boxes are not covered and some are not full. For these other boxes, a mechanism is provided which has a blade enter the box and slide on a rod to tightly press all the cards against one end of the box to hold them in the box during optical alignment.
This known, self-adjusting card loader suffers from a number of disadvantages. First, since card alignment is with the top edges of the cards pointed downward, the photoptical sensor equipment including the scan mechanism which moves the sensor across the rack must be located directly beneath open boxes. Any chaff or other debris in or on the box, as well as loose cards, which fall, fall toward and possibly into contact with the optical equipment or the scan mechanism. Second, cards are capable of falling out of the boxes turned upside down if the blade pressure is insufficient; dropped cards can be lost or damaged or cause damage to the counter. Thirdly, the entire loading sequence is complicated by multiple steps which take a relatively long time simply to load, count and unload. The complication creates equipment maintenance problems, makes the counter difficult to operate and increases labor cost.